Bunker underneath the Koblenz Ehrenbreitstein fortress, Koblenz, Rhineland-Palatinate, Germany, Europe

architecture bastion bastions bunker bunker bunkers castle castles design ehrenbreitstein europe european federal fortification fortifications fortress fortresses frg german germany inboard indoor indoors inside interior internal koblenz nobody of palatinate photo republic rhineland rhineland palatinate stronghold strongholds the underground underneath view views